The present invention relates to a general-purpose size filter cartridge for liquid filtration, which extensively increases service life for filtration.
The thread-winding depth type cartridge filter, comprising cylindrical hard porous core with threads wound on it, has been widely used in the past because this can be produced at relatively low cost with high accuracy to meet wide variety of needs in the industrial fields.
However, when variation occurs in filtration accuracy due to irregular winding of threads or when liquid with high viscosity is to be filtered, winding mesh may be widened by high penetrating pressure. To solve this problem, a cartridge filter using nonwoven glass fiber fabric between upper and lower thread-winding layers has been used as a filter indispensable for the paint and ink industries. In such filter, the lower thread-winding layer is primarily used for preventing the glassfiber from falling off, while the upper thread-winding layer serves as a pre-filter, and the filtration is substantially performed by nonwoven glassfiber fabrics.
Moreover, the conventional depth type cartridge filter as described above does not completely satisfy the requirements in practical application in terms of service life for filtration, and there are imminent demands on a cartridge filter with longer service life.